基于地统计学的路基连续压实均匀性评价

传统的路基压实质量均匀性评价方法均基于变异系数等概率统计指标，未能考虑检测数据的空间分布特性，难以准确评价路基压实质量的不均匀性。基于地统计学理论，建立半变异函数模型描述连续压实检测数据的空间变异性，采用指数模型对半变异函数曲线进行最优拟合，并提出偏基台值C作为路基压实均匀性控制指标。分别采用地统计方法与传统数理统计法对沪昆客运专线芷江试验段的路基进行压实均匀性评价。结果表明：在压路机振动频率波动或存在压实薄弱区域的情况下，与传统数理统计指标变异系数Cv相比，地统计指标C可消除系统误差等随机性因素对均匀性评价结果的影响，更能客观反映不同工况下的填筑土体在空间上的不均匀压实状态，其结果为铁路路基压实均匀性评价提供了新的思路。

Evaluation of roller-integrated compaction uniformity based on geostatistics

Traditional methods for the quantification of subgrade compaction uniformity are all based on the univariate parameters, such as the deviation coefficient. However, these parameters are unable to consider the spatial distribution of the collected data and evaluate the non-uniformity of the compaction state. The semivariogram is modeled to characterize the spatial variation of the compaction values(CV) based on the geostatistics. Then the exponential model is utilized to fit the calculated semivariogram curve. Finally the sill value C is obtained as the uniformity indicator to ensure the subgrade compaction quality. Both the suggested geostatistical method and traditional statistical method are employed to assess the compaction uniformity of the experimental subgrades in Zhijiang construction site of Shanghai-Kunming Passenger Dedicated Line. The results demonstrate that, different from the univariate parameter Cv, the proposed parameter C can not only eliminate the influence of the uncertain factors such as systematic error, but also provide a more objective evaluation on the spatial non-uniform distribution of the subgrade compaction state. The compaction uniformity evaluation specification can be significantly improved by the suggested method.